Suspension Upgrades - Turbo Buick Basics, Part 10

Part 10 of our series.

In our last episode (April 2012), we strip-tested our buddy Tim Cairone's Turbo Buick in its latest state of tune (365 rwhp, 554 lb-ft at 18 psi). With all that torque, we knew it needed help getting the power to the pavement. So we ordered Air Lift airbags from G Body Parts and a Lift Bar Set-Up (lower control arms with relocation brackets) from UMI Performance. Each component was installed and individually tested at Atco Dragway on different track days.

First we tested the airbags, which allowed us to dial in the rear for some preload; added bite resulted. Then we went back with the UMI Lift Bars to gain great hook with an 8-psi boost launch, when before we couldn't launch at more than 5 psi without wheelspin. The airbags teamed with the lift bars helped us achieve our best 60-foot (1.55) and quarter-mile e.t. of 11.41 at 117.94 mph. Still, with today's ever expanding technology, there are more upgrades available for making improvements.

We knew better e.t.'s were possible if we could launch at more than 8 psi without brake creep. To have higher boost launches (10-12 psi) we needed a special brake kit with more holding power, available through G Body Parts. With the expected higher boost launches, additional beefing up of the rear suspension for more strength and traction would be beneficial towards better short times in Tim's Buick.

Once again we looked to the experts at UMI Performance for adjustable upper control arms and frame braces to complete the rear suspension setup. Added insurance in traction and road-holding would come from adjustable QA1 shocks for all four corners. When the QA1s are adjusted for drag racing, the front end will rise easier, to transfer the weight to the rear and plant the rear tires to the pavement.

Installation of the special brake package, control arms, frame braces, and shocks was handled at the GN owner's shop, Shore Wheels (Tuckerton, New Jersey). Some street bashing made sure the rear brake shoes were seated, then they were readjusted and the brakes bled properly. The aforementioned was necessary so the GN would be ready when back at our favorite testing grounds, Atco Raceway. The new G Body Parts special brake package enabled higher boost launches.

Working with the UMI and QA1 suspension components, the Turbo Buick was hookin' and bookin'. The launch (front-end rise and rear tires planting) never felt better, and road-holding was much improved. Now the Buick is ready to safely go into the 10s if we feel the need for more speed.

Check out our latest suspension upgrades and how they benefited the Turbo G-body to become a better all around package.

MORE PHOTOS

VIEW FULL GALLERY

xclose

Suspension Upgrades - Turbo Buick Basics, Part 10

1 To hold more boost at the line, we ordered this brake upgrade kit from G Body Parts ($179.95). It consists of two pair of long brake shoes, two GM AC Delco S-10 wheel cylinders, and three stainless steel brake-hose lines. Besides giving us more holding power on the starting line, it will help reduce stopping distance.

1 To hold more boost at the line, we ordered this brake upgrade kit from G Body Parts ($179.95). It consists of two pair of long brake shoes, two GM AC Delco S-10 wheel cylinders, and three stainless steel brake-hose lines. Besides giving us more holding power on the starting line, it will help reduce stopping distance.

2a The original stock brake proportioning valve (top) was replaced with a brass proportioning valve from G Body Parts ($89.95). The original iron prop valve was recalled by GM because it deteriorated and caused damage to the accumulator ball.

12a We installed the new UCAs and braces one side at a time. The longer bolts from the brace kit for the LCAs and the UCAs were installed; you only need to let the threads stick out 1 to 11⁄2-inches for installment of the braces.

12b Note the bottom picture features the UMI Performance LCA from Turbo Buick Basics, Part 9.

13a Locate the new frame brace; install it on the upper bolt first and attempt to install it on the lower bolt.

2b G Body recommends this upgrade when doing its brake package, and we needed to bleed the front and rear brakes anyways after installing the kit.

3 All three of the factory rubber brake hose lines were replaced with the stainless steel lines from the G Body brake upgrade kit. The stock rubber lines expand, causing a delay and loss of pressure to the calipers and wheel cylinders. With the new stainless lines, expansion is non-existent.

4 Here it’s easy to note the bore size difference in the stock wheel cylinder and the S-10 wheel cylinder included in the G Body brake upgrade kit. Tim thought he upgraded to S-10 wheel cylinders a couple years ago, but the auto parts stores have superseded the original larger bore S-10 wheel cylinder with a regular smaller bore passenger-car wheel cylinder years ago to prevent rear brake lockup on the light-rear-end S-10 pickup truck. Thankfully you can get the real S-10 wheel cylinders from G Body parts.

15 Don’t forget to grease the grease-able polyurethane bushings for easy suspension movement. Next, the car was lowered. Then we gave the suspension plenty of up and down movement (15-20 times). Again, wait till the car is at rest with the suspension loaded to tighten the nuts and bolts. Torque all the control arm bolts to 90 ft-lb.

16a The pinion angle didn’t change with the new UCAs installed.

16b So we loosened both jam nuts on the adjuster of each control arm. With a 1-inch wrench, each adjuster was turned a half of a turn each until we reach our desired 2-degree downward pinion angle setting.

13b Lengthen or shorten the frame brace as needed to install it on both bolts. The left picture shows the L/R brace and the right features the R/R brace. Do not tighten the nuts and bolts until the car is at rest with the suspension loaded.

14a We ditched the garden-variety shocks (left) for the QA1 adjustable units (right).

5b The S-10 wheel cylinders with their larger bore and pistons will apply more pressure to the brake shoes for more holding and stopping power.

6a Normally there’s a long and a short brake shoe with drum brakes. The longer shoe faces the rear, and the shorter shoe faces the front of the vehicle. In the left photo, the surface area is about 2-inches shorter on the used brake shoe. The right picture shows both of the long shoes from the brake upgrade kit in place after installation.

17 The new suspension components from Part 9 along with the new QA1s look great, but this shot also shows the rearend housing is in dire need of paint and detailing. Not seen are the braces and UCAs we just installed and couldn’t wait to test. Tim mentioned his Turbo Regal never rode or handled better out on the road.

18 A simple turn of the knob will make adjustments for street, strip, road course, or autocross conditions. On the street, Tim liked the nice riding, road-holding feel with a setting of only two clicks on both the front and rear shocks. At the track we’ve found the QA1s work well with one click on the front (for fast front-end rise) and five to eight clicks on the rear shocks (helps keep the rear tires planted to the pavement). For our strip test, we tried one click front and five clicks rear and didn’t have a hint of tire spin even with 12-psi boost launches.

19 Here it’s noticeable the rear tires are digging into Atco’s tarmac. Check out the front-end rise—at this point the GN is roughly 40-50 feet off the line at full boost (18 psi). Weather was 20-degrees warmer (67 degrees), still we managed better 60-foot e.t.’s with 10 to 12 psi boost launches (thanks to the brake upgrade package, previously 8-psi boost launches were max). Our first pass was the quickest (1.51 60-foot, 11.38 at 117 mph) when the chilled-boost Buick (18-psi max boost) was at its coolest temperature. We know with more boost and a higher stall converter, the little forced-air V-6 could propel the G-body into the 10s. For now Tim is quite satisfied with his street tune and thrill-to-drive Turbo Buick. Our goals surpassed Tim’s expectations of making his GN a faster and better driver than most of the latest performance cars out there.

6b Normally there’s a long and a short brake shoe with drum brakes. The longer shoe faces the rear, and the shorter shoe faces the front of the vehicle. In the left photo, the surface area is about 2-inches shorter on the used brake shoe. The right picture shows both of the long shoes from the brake upgrade kit in place after installation. By using the longer/softer brake shoes in conjunction with the S-10 wheel cylinders, we’ll gain more brake holding power at the starting line for higher boost launches.

8 Additional beef to the Buick’s back end will come from these UMI Performance Tubular Frame Brace/Control Arm Reinforcements (PN 3028, $119.99). These tubular reinforcement braces tie the upper and lower control arm mounts together for added strength to the frame mounting area. They are adjustable in length to ensure a perfect fit. The brace kit includes new longer Grade 8 bolts, lock nuts, and washers for a bolt-in installation.

9 Your author has dragstrip and skidpad (roadholding ability) tested QA1 shocks on other musclecars through the years with great results. With their easy knob adjustment, the QA1s can be adjusted for better hook at the strip, handling for the road course or autocross, and easier ride on the street. We ordered QA1 Stocker Star single-adjustable (18-way) shocks through UMI. For the front, we ordered TS 505; the rears are TS 801, which go for $148.

10 Before we began installation, we measured the driveshaft angle (shown here) and the pinion angle on the bottom end of the rearend pinion yoke housing. Be sure the vehicle is level and at rest (suspension loaded) before recording the angle. We recorded 3 degrees at both. To achieve true pinion angle, you must add the two measurements. UMI has found the best settings for a street driven car are 1-2 degrees downward.

11 Once the wimpy stock UCA was removed, it was placed next to the new stronger adjustable UCA from UMI Performance. The UMI arms come preset at factory length, and will not flex or deflect like a stock UCA to keep the pinion angle in check for superior hook and road handling.

In Part 8, we discuss some of the tuning tips and tricks that you will need to keep in mind and know to get better driving and less lag. We get some help from RJC, Caspers, Precision Turbo, Turbo Tweak and last but not least, Tune Time Performance. - GM High-Tech Performance Magazine » Read More